I installed floating buttons. Selected Menu assignment on all pages. I've published it with various positions, each time without success.
I use SP Pagebuilder which may be the issue. I am guessing your extension has to be tweaked to work with Pagebuilder and I don't know how to do that (if it is even possible).
The extension is one of the nicest I've seen and it is a bit disappointing it doesn't work on the site I'm building.
Hopefully you may have a solution.